Devices for the measuring of angles are already widely known. Thus, for example, an adjustable tri-square is known, one leg of which tri-square has a number of successively positioned notches which correspond to the various angular positions. One of the legs is movably hinged and can be adjusted and clamped in a selected angular position. Adjacent surfaces which converge at a common angle are mounted for the individual notches, between which countersurfaces the other leg is pressed with a wedge-shaped part after each respective transverse movement and in this manner the desired angular relationship is determined. This device, however, requires a direct access to the axis of rotation of the surfaces which are movable with respect to one another and even then does not result in the desired angular precision necessary in modern aircraft construction.
The basic purpose of the invention is to produce an angle measuring device, in which the measurement is unaffected by translatory movements of the planes which are to be measured and which does not require access to the axis of rotation.
This purpose is attained by hingedly associating two parallelogram-forming rails with a scale disk bearing a vernier wherein the parallelograms are connected to lockable feet through suitable pivot bearings and universal pivot bearings so that translatory position changes of the planes in directions z and x have no effect on the measurement. These measures prevent translational changes in position of the individual planes with respect to one another from affecting the result of the measurement. Measurements of angles are also possible when the plane in which the measurement is taken does not lie perpendicular with respect to the break-line and when in general the surfaces to be measured do not lie in a single plane.
A further development of the invention provides that an electric pick-up is associated with the scale disk for the electric indication and registration of the measurement. These measures improve the reading reliability and exactness.
Furthermore it is provided that the vernier is constructed adjustably and lockably for the zero-point adjustment and has for this purpose a regulator wheel and a clamping screw. This permits a close adjustment and precision in the resulting measurement.
Furthermore it is provided that a bar for preadjusting the device in one direction is associated with the parallelogram. This permits a widening of the measuring range in the oppposite direction.
One embodiment provides that the feet are provided with holding and clamping devices and are adjustable selectively through an angle of 90.degree.. This provides an easier adjustment of the device to various measuring problems.
The invention is hereinafter described and illustrated in connection with an exemplary embodiment.